Bismuth Oxychloride Nanoparticles: Deep Eutectic Solvent Assisted Synthesis and Application in an Electrochemical Nickel Sensor

Abstract A safe, green, and cost‐effective procedure is introduced for synthesizing bismuth oxychloride (BiOCl) nanoparticles as an alternative to the time‐consuming ones with hazardous chemicals. In this regard, BiOCl was synthesized in both nanoplates and nanoflowers morphologies employing choline chloride: a urea‐based deep eutectic solvent, as a green solvent through the popular solvothermal and anion exchange synthesis approach. Accordingly, nano‐flowers and nano‐plates of BiOCl were synthesized by exposing {010} and {001} facets, respectively, while different characterization techniques showed excellent patterns and high purity of the synthesized nanoparticles. They are exploited as electrode modifiers for fabricating a high‐performance electrochemical nickel ion sensor to control the quality of water, and industrial waste liquor concentrates. The adsorption stripping voltammetry technique revealed that the electrode used for nickel detection with BiOCl nano‐plates was more sensitive than with BiOCl nano‐flowers. To achieve optimal electrochemical values for the proposed sensor, variables interactions are investigated using the central composite design method. The limit of detection, the electron transfer coefficient, and the number of transferred electrons were obtained to be 0.26 μ m , 0.166, and 1, respectively. Evaluating the sensor application in the presence of other heavy metal cations showed its promising capability of nickel ion detection in real samples.